Simple bash if statement for usage

Bash Scripting Argument Usage Checker

#!/bin/bash

if [ $# -eq 0 ]; then
echo "Usage: $0 -n [number] -m [message] -u [username] -p [password]";
echo "";
echo "[number] = SMS number to send message to";
echo "[message] = Text of message you want to send";
echo "[username] = Username assocated with aql account";
echo "[password] = Password assocated with aql account";
echo " Both the username and password options are optional and";
echo " override the account credentials defined in this script.";
echo "";
exit 1;
fi